CN112640629A - Pneumatic distribution system - Google Patents

Abstract

A pneumatic dispensing system for dispensing a granular product to an agricultural implement includes a valve assembly fluidly coupled between a storage tank and a main pipe. The storage tank is configured to store the granular product. The main conduit is configured to pneumatically convey the particulate product to the agricultural implement by directing an airflow from a first portion of the main conduit having a larger cross-sectional area to a second portion of the main conduit having a smaller cross-sectional area. The valve assembly selectively causes airflow from the main pipe into the sump until a first static pressure in the sump is greater than a threshold amount of a second static pressure in a second portion of the main pipe.

Description

Pneumatic distribution system

Technical Field

The present invention relates generally to agricultural product dispensing systems and, more particularly, to pneumatic dispensing control of granular products.

Background

Typically, a planter (e.g., a planter) can be towed behind an off-road vehicle (e.g., a tractor) by a mounting bracket secured to a rigid frame of the planter. The seed planting implement may include a plurality of row units distributed across the width of the implement. More specifically, each row of devices can seed at a desired depth below the surface of the field soil as the planter is towed. For example, each row of devices may include a ground engaging tool or furrow opener that forms a sowing path (e.g., a trench) into the soil. The seed tube may then deposit a granular product (e.g., seed or fertilizer) into the trench. The closing disks may move excavated soil back into the particle covered trench as the earthmoving machine traverses the field. In this way, rows of seeds can be planted.

In some configurations, the granular product may be delivered to the row units of the planter from a centralized location (e.g., a pneumatic cart). The gas cart typically includes a seed storage tank (e.g., a pressurized tank), an air source (e.g., a blower), and a metering assembly. More specifically, the particulate product may be gravity fed from the tank into a metering assembly that distributes a desired flow rate of the particulate product to each row of devices. For example, the air source may generate an air flow, and the metering assembly may control the flow of seeds into the air flow such that the seeds are entrained in the air flow. The gas stream may then be conveyed to each row unit through a fluidly coupled primary line between the metering assembly and the row unit, thereby conveying the particulate product to each row unit. Thus, by maintaining a desired relationship between the static pressure in the tank and the static pressure in the main pipe, the desired seed deposit can be promoted. When the difference between the static pressure in the sump and the main conduit is outside the desired range, it may interfere with the seed flow, thereby providing an undesirable seed flow rate to the row device.

Disclosure of Invention

The following outlines certain embodiments commensurate with the scope of the originally claimed invention. These embodiments are not intended to limit the scope of the claimed invention but, rather, are intended to provide a brief summary of possible forms of the invention. Indeed, the invention may encompass a variety of forms that may be similar or different from the embodiments described below.

In one embodiment, a pneumatic dispensing system for dispensing a granular product to an agricultural implement includes a first pressure sensor, a second pressure sensor, a valve, and a controller. The first pressure sensor is configured to be fluidly coupled to the particulate product storage tank and to output a first signal indicative of a first static pressure in the storage tank. The second pressure sensor is configured to be fluidly coupled to a main conduit that pneumatically delivers the granular product to the implement by directing an airflow from a first portion having a larger cross-sectional area to a second portion having a smaller cross-sectional area. The second pressure sensor outputs a signal indicative of static pressure in a second portion of the main conduit. The valve is configured to be fluidly coupled between the sump and the main conduit and to selectively allow airflow from the main conduit to the sump. A controller is communicatively coupled to the pressure sensor and the valve and instructs the valve to direct the flow of air from the main conduit to the tank until the first static pressure is greater than a threshold amount of the second static pressure.

In another embodiment, a pneumatic valve for a produce dispensing system includes a fan inlet, a tank outlet, a shuttle valve, a control pressure inlet, and a diaphragm. The fan inlet is configured to be fluidly coupled to an air source that supplies an airflow to a main duct. The first section of the main line facilitates distribution of the granular product to the implement by directing an air flow from the first section to a second section of the main line, the first section having a greater cross-sectional area than the second section. The tank outlet is configured to be fluidly connected to a storage tank storing the particulate product and to facilitate a flow of the particulate product to the second portion of the main line. The shed comprises a shed. The control pressure inlet is configured to be fluidly coupled to a second portion of the main conduit or meter housing. The diaphragm has a first side and a second side. The first side is connected to a shuttle valve exposed to a static pressure within the tank through the tank outlet. The second side of the diaphragm is exposed to a static pressure of the main conduit or the second section of the meter housing through the control pressure inlet. The diaphragm is configured to move toward the tank outlet such that the shuttle aperture is aligned with the fan inlet when the static pressure in the tank is not greater than a threshold amount of static pressure in the main conduit or the second portion of the instrument housing.

In yet another embodiment, a pneumatic dispensing system configured to dispense a granular product to an agricultural implement, wherein the pneumatic dispensing system comprises a first pressure sensor, a second pressure sensor, a valve, and a controller. The first pressure sensor is configured to be fluidly coupled to a storage tank that stores a particulate product. The first pressure sensor is configured to output a first signal indicative of a first static pressure in the tank. The second pressure sensor is configured to be fluidly coupled to the meter housing. The second pressure sensor is configured to output a second signal indicative of a second static pressure in the meter housing. The valve is configured to be fluidly coupled between the tank and the main conduit. The valve is configured to selectively allow airflow from the main conduit to the sump. The controller is communicatively coupled with the first pressure sensor, the second pressure sensor, and the valve. The controller is configured to instruct the valve to flow the gas flow from the main conduit into the tank until the first static pressure is greater than a threshold amount of the second static pressure.

Drawings

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

FIG. 1 is a side view of an air vehicle (including an agricultural product dispensing system) according to an embodiment;

FIG. 2 is a schematic view of the produce dispensing system of FIG. 1, according to an embodiment;

FIG. 3 is a cross-sectional perspective view of an embodiment of a valve that may be used with the produce dispensing system of FIG. 1;

FIG. 4 is an exploded view of the valve of FIG. 3;

fig. 5 is a flow chart of a process of controlling pressure in an agricultural product dispensing system according to an embodiment.

Detailed Description

One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

Generally, the produce dispensing system may include a towable agricultural implement for depositing granular produce into the soil. As used herein, the granular product may be any suitable granular material that needs to be deposited onto the ground, such as various types of seeds and fertilizers. However, to simplify the following discussion, the product is described as a seed. However, one or ordinary skill in the art will recognize that the techniques described herein may be readily adapted for use with other products.

More specifically, the implement may include row units that open the soil, dispense granular product into the soil openings, and reclose the soil as the implement is towed through the field, for example, by an off-road work vehicle (e.g., tractor). Additionally, the produce dispensing system may include a pneumatic vehicle for dispensing granular produce to a row of implements on the implement. More specifically, in some embodiments, a metering assembly on the gas car may pneumatically dispense the particulate product to the row device. For example, the metering assembly may control the output of the particulate product from the reservoir to the air stream, which is then delivered to the row device via a pneumatic line (e.g., including a main line connected to an air cart) that fluidly connects the metering assembly to the row device.

The cross-sectional area of the main line may vary (e.g. shrink) over its length. Thus, pressure variations in the primary circuit may be caused by the venturi effect. The difference between the static pressure in the tank and the static pressure in the primary line may adversely affect the flow rate of the particulate product out of the tank and into the primary line due to venturi effects or other factors. For example, when the static pressure in the storage tank is greater than a desired value above the static pressure at the change in cross-sectional area (e.g., the venturi section), the particulate product may flow out of the storage tank at a higher velocity than desired. Alternatively, when the static pressure at the change in cross-sectional area (e.g., the venturi section) exceeds the static pressure in the storage tank, the particulate product may flow out of the storage tank at a rate that is less than desired.

Thus, as will be described in greater detail below, embodiments described herein may improve product flow consistency of a product dispensing system by controlling static pressure in the product dispensing system (e.g., in a tank). For example, one embodiment discusses a pneumatic dispensing for dispensing a granular product to an agricultural implement including at least two pressure sensors, a valve, and a controller. A first pressure sensor is fluidly coupled to the particulate product storage tank and outputs a first signal indicative of a first static pressure in the storage tank. The second pressure sensor is fluidly coupled to a main conduit that pneumatically delivers the granular product to the agricultural implement by directing a flow of air from a first section of greater cross-sectional area to a second section of lesser cross-sectional area.

Then a larger cross-sectional area portion which provides product for the row unit. The second pressure sensor outputs a second signal indicative of a second static pressure in a second portion of the main conduit. In addition, or as an alternative to the second pressure sensor, a third pressure sensor may be fluidly coupled to the meter housing. The third pressure sensor outputs a third signal indicative of a third static pressure in the meter housing (e.g., a static pressure at an edge of a meter wheel). In addition, or as an alternative to the second pressure sensor, the fourth pressure sensor may be fluidly coupled to a second line for pressurizing the storage tank. The fourth pressure sensor outputs a fourth signal indicative of a fourth static pressure in the second line. However, it should be understood that any combination of sensors is possible. For example, the disclosed technology may use a first or fourth pressure sensor and a second or third pressure sensor. The valve is fluidly coupled between the sump and the main conduit and selectively allows airflow from the main conduit to the sump. A controller is in communication with the pressure sensor and the valve and instructs the valve to flow gas from the main conduit to the tank until the first static pressure is greater than a threshold amount of the second static pressure.

To facilitate illustration, FIG. 1 shows a side view of a gas cart 10 that may be used with a towable implement to deposit seeds into soil. More specifically, the aircart 10 may be used to centrally store and distribute seeds to agricultural implements. Accordingly, in the illustrated embodiment, the gas cart 10 includes a storage tank 12, a frame 14, wheels 16, a metering assembly 18, and an air source 20. In the depicted embodiment, the aircar frame 14 may be coupled to an agricultural implement or off-road work vehicle by a hitch 19. Thus, the wheels 16 may contact the soil surface to enable the air transporter 10 to be towed.

Further, the storage tank 12 may store seeds collectively prior to dispensing. In some embodiments, the reservoir 12 may include multiple compartments for storing various flowable particulate products 26. For example, one compartment may include seeds, such as rapeseed oil or mustard, and another compartment may include dry fertilizer. In the illustrated embodiment, the gas car 10 may dispense seeds, fertilizer, or a mixture thereof to an agricultural implement.

Further, as shown, a metering assembly 18 is connected to the bottom of the tank 12. More specifically, the metering assembly 18 may allow seeds stored in the storage tank 12 to be gravity fed into the metering assembly 18. The metering system 18 may then control the flow of seeds into the air stream generated by the air source 20, thereby controlling the distribution of seeds to the row units for deposition into the soil. In some embodiments, for example, the air source 20 may be a pump or blower driven by an electric or hydraulic motor.

For clarity of illustration, a schematic view of the pneumatic dispensing system 21 is shown in FIG. 2. As shown, the pneumatic dispensing system 21 includes an air source 20, a reservoir 12, and a metering assembly 18. More specifically, the main conduit 22 is used to direct an airflow 24 generated by the air source 20 through the metering assembly 18. It will be appreciated that a system having a plurality of tanks 12 and metering assemblies may have a plurality of main conduits 22. In addition, the metering assembly 18 includes a meter housing 27 and a meter roller 28 for controlling the flow of seeds 26 into the air stream 24. Although only one meter roll 28 is depicted, in other embodiments, the metering assembly 18 may include a plurality of meter rolls 28 disposed adjacent to each other along the longitudinal axis.

As shown, the meter roller 28 includes an interior cavity 30, and the interior cavity 30 may receive a shaft that drives rotation of the meter roller 28. In the depicted embodiment, the cavity 30 has a hexagonal cross-section. However, alternate embodiments may include various other cavity configurations (e.g., triangular, square, keyed, splined, etc.). In some embodiments, the shaft may be connected to a drive device, such as an electric or hydraulic motor, to rotate the rice roll 28. Additionally or alternatively, the meter roller 28 may be coupled to the wheel 16 through a gear assembly such that rotation of the wheel 16 drives rotation of the meter roller 28. Such an arrangement would automatically change the speed of rotation of the rice roller 28 based on the speed of the aircar 10.

Further, the rice roller 28 may include a plurality of grooves 32 and recesses 34. The number and geometry of the grooves 32 may be selected to accommodate the seeds 26 being dispensed. For example, in the illustrated embodiment, the rice roller 28 includes six grooves 32 and a corresponding number of grooves 34. In other embodiments, the rice roller 28 may include more or fewer grooves 32 or recesses 34. For example, the rice roller 28 may include 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 or more grooves 32 or flutes 34. In addition, the depth of the groove 34 or the height of the groove 32 may be selected to accommodate the produce 26 in the storage tank 12. For example, for larger seeds, a rice roller 28 having deeper grooves 34 and fewer grooves 32 may be used, while for smaller seeds, a rice roller having shallower grooves 34 and more grooves 32 may be used. Other parameters, such as slot pitch (i.e., the angle of the slot with respect to the longitudinal axis) and slot angle (i.e., the angle of the slot with respect to the radial axis) may also be varied in alternative embodiments.

The rotational speed of the rice roller 28 can control the flow rate of the seeds 26 into the air stream 24 for a particular rice roller 28 configuration. For example, when the rice roller 28 rotates, the seeds 26 fixed in the notches 34 of the rice roller 28 are transferred to the main line 22 through the outlet 36. The seeds 26 may then be entrained in the air flow 24, thereby forming an air/seed mixture 38. The mixture 38 may then flow through pneumatic lines to the row unit of the implement where the seeds or fertilizer are deposited in the soil.

As shown, the main line 22 converges from a first cross-sectional area 40 to a second cross-sectional area 42 before reaching the outlet 36, and then diverges to a third cross-sectional area 46 after forming the air/seed mixture 38. The difference in the static pressure in the storage tank 12, the static pressure in the meter housing 27, and the static pressure in the main conduit 22 may adversely affect the flow rate of the seeds 26 out of the storage tank 12 and into the main conduit 22. Due to the venturi effect, changes in the cross-sectional area of the main conduit 22 may result in pressure changes in the main conduit 22 (e.g., the venturi 44 section). Variations in the static pressure of the tank 12, the static pressure in the meter housing 27, and the static pressure of the main conduit 22 may also be caused by factors other than the venturi effect. For example, when the static pressure in the storage tank 12 is higher than a desired value of the static pressure in the meter housing 27 or the main pipeline 22, the seeds 26 may flow out of the storage tank 12 at a higher rate than desired. Alternatively, the seeds 26 may flow out of the storage tank 12 at a slower rate than desired when the static pressure in the main line 22 or the static pressure in the metering section exceeds the static pressure in the storage tank 12.

Thus, one way to maintain predictable seed 26 flow into the main conduit 22 is to measure and control the differential pressure across the rice roll 28 (e.g., by monitoring the static pressure PS1 in the tank 12, the static pressure PS2 in the main conduit 22, or the static pressure PS3 in the meter housing 27). More specifically, a first pressure sensor 48 is fluidly coupled to the storage tank 12 to facilitate determining PS1, a second pressure sensor 49 is fluidly coupled to the main line 22 to facilitate determining PS2, and a third pressure sensor 50 is fluidly coupled to the meter housing 27 (e.g., mounted at an edge of the meter wheel 28 of the meter housing 27). If pneumatic distribution system 21 includes multiple main lines 22, each main line 22 may have its own pressure sensor 49. One advantage of fluidly coupling the pressure sensor to meter housing 27 (rather than fluidly coupling the pressure sensor to primary conduits 22) is that in configurations having multiple primary conduits 22, only one pressure sensor 50 is used per primary conduit 22, rather than one pressure sensor 49. In some embodiments, the pneumatic dispensing system may include a fourth pressure sensor 51, the fourth pressure sensor 51 being fluidly coupled to a second conduit 52, the second conduit 52 fluidly coupling the main conduit 22 to the storage tank 12. Auxiliary line 52 facilitates the adjustment of static pressures PS1, PS2, PS3, and PS 4. Each pressure sensor is configured to output a respective signal indicative of the determined pressure. Additionally, a valve 54 fluidly coupled to the secondary line 52 may be used to enable or disable the flow of air 24 through the secondary line 52 and into the tank 12. As previously mentioned, it should be understood that any combination of pressure sensors is possible. For example, the pneumatic dispensing system may include a front 48 or fourth pressure sensor 51 and a second 49 or third pressure sensor 50.

To facilitate measuring and controlling static pressures PS1, PS2, PS3, and PS4, controller 56 may be communicatively coupled to first pressure sensor 48, second pressure sensor 49, third pressure sensor 50, fourth pressure sensor 51, and valve 54. For example, the controller 56 determines PS1 from the signal received from the first pressure sensor 48, PS2 determines PS1 from the signal received from the second pressure sensor 49, PS3 is based on the signal received from the third pressure sensor 50, PS4 is based on the signal received from the fourth pressure sensor 51, or controls the operation of the valve 54 by sending commands to the valve 54. In one embodiment, the valve shown in FIG. 2 may be operated by a solenoid. Accordingly, the controller 56 may include a processor 60 and a memory 58. In some embodiments, processor 60 may include one or more general-purpose processors, one or more application-specific integrated circuits, one or more field programmable gate arrays, or the like. Further, memory 58 may be any tangible, non-transitory, computer-readable medium capable of storing instructions executable by processor 60 or data processable by processor 60. In other words, the memory 58 may include volatile memory, such as random access memory, or non-volatile memory, such as a hard disk drive, read only memory, optical disks, flash memory, and the like.

More specifically, the controller 56 may instruct the valve 54 to adjust its position (e.g., direction) to control the static pressure such that the static pressure ps1 in the storage tank 12 or the static pressure ps4 in the secondary line 52 is greater than the static pressure ps3 at the main line 22 or the meter housing 27 to a desired threshold. For example, the desired range of difference between static pressure ps1 in the tank 12 or static pressure ps4 in the secondary line 52 and static pressure ps2 in the venturi 44 section or static pressure ps3 in the meter housing 27 may be between 0.125 kilopascals and 1.246 kilopascals, or between 0.125 kilopascals and 0.249 kilopascals.

However, it should be understood that the above-described embodiment is merely one embodiment, and other configurations may be possible. For example, other embodiments may only have a pressure sensor 48 fluidly coupled to the tank 12 and a pressure sensor 49 fluidly coupled to the main line. Additionally, other embodiments may only have a pressure sensor 48 fluidly coupled to the tank 12 or a pressure sensor 51 fluidly coupled to an auxiliary line 52 and a pressure sensor 50 fluidly coupled to the meter housing 27. Another embodiment may have a pressure sensor 49 fluidly coupled to the main conduit and a pressure sensor fluidly coupled to the meter housing 27. In these embodiments, the techniques described (e.g., operating valve 54 on secondary line 52 based on differential pressure) may be used to control the pressure in the system to achieve and maintain a desired relationship between the measured pressures. For example, operation of the valve 54 may maintain the measured pressure upstream of the meter housing 27 above a threshold value of the measured pressure downstream of the meter housing 27. In the illustrated embodiment, the valve assembly 53 includes a valve 54 operated by a controller 56. However, in other embodiments, the valve assembly may include an automatic valve disposed along the secondary line 52 and fluidly connected to the meter housing 27 by a control pressure line 55.

Fig. 3 shows a perspective view of an embodiment of the valve 61. The valve 61 is an automatic valve. Unlike the valve 54 shown in fig. 2, the valve 61 shown in fig. 3 is not operated by the controller. It should be understood that the systems and methods described herein may be implemented with electronically controlled valves, automated valves, or any other type of valve. As shown, the valve 61 includes a first housing 62, a second housing 64, a control pressure inlet 66, a spring 68, a diaphragm 70, a washer 72, a bolt hole 74, a shuttle valve 76 having a first shuttle hole 78 and a second shuttle hole 79, and a fan inlet 80. More specifically, in the depicted embodiment, the first housing 62 and the second housing 64 are flanged such that the diaphragm 70 is sandwiched therebetween. Further, as shown, the second housing 64 includes a control pressure inlet 66 that may be fluidly coupled with the venturi portion 44 or the instrument housing 27. The spring 68 is disposed within the second housing 64 such that the spring 68 is substantially coaxial with the second housing 64. The spring 68 is selected such that the spring constant of the spring 68 exerts a force corresponding to a desired threshold difference between the static pressure ps4 in the secondary line or the static pressure ps1 (which should be similar) in the tank 12 and the static pressure. PS2 in the main line 22 or PS3 in the meter housing 27. More specifically, the spring 68 abuts the back face of the second housing 64 at one end and the first washer 72 at the other end, thus urging the diaphragm 70 toward the first housing 62 when the diaphragm 70 is exposed to PS2 or PS3 (e.g., pressure in the venturi portion 44 or pressure in the meter housing 27) through the control pressure inlet 66.

Further, as shown, the diaphragm 70 is sandwiched between a first gasket 72 on one side and a second gasket 72 on the other side. Bolt holes 74 in the diaphragm 70 align with holes in the washer 72, enabling the bolts to secure the diaphragm 70, washer 72, and shuttle valve 76 together. A shuttle valve 76 with a first shuttle aperture 78 and a second shuttle aperture 79 rests on the second washer 72. Air in the shuttle valve 76 is below PS1 (e.g., pressure in the tank 12) or PS4 (e.g., pressure in the secondary line) and flows into the first housing 62 through the secondary shuttle valve aperture 79, exposing the diaphragm to PS1 (e.g., pressure in the tank 12) or PS4 (e.g., pressure in the secondary line). It should be understood that although two circular second shuttle holes 79 are shown on the space shuttle 76, the number of second shuttle holes 79 may not be large and the second shuttle holes 79 may be of any shape so long as the second shuttle holes allow air to flow from the shed into the first housing 62. When PS2 (e.g., the pressure in venturi 44 section) or PS3 (e.g., the pressure in meter housing 27) is greater than PS1 (e.g., the pressure in storage tank 12) or PS4 (e.g., the pressure in secondary conduit 52), air drawn from venturi 44 section or meter housing 27 enters second housing 64 through control pressure inlet 66, and the pressure established in second housing 64 is higher than the pressure in first housing 62. In response, the diaphragm 70 moves toward the first housing 62, urging the shuttle valve 76 toward the tank inlet 52 and aligning the first shuttle valve aperture 78 with the fan inlet 80, thereby allowing air 24 to flow into the tank 12, thereby increasing the PS 1. When ps1 (e.g., pressure in tank 12) or ps4 (e.g., pressure in secondary line 52) is greater than the desired amount of ps2 (e.g., pressure in venturi 44 portion) or ps3 (e.g., pressure in meter housing 27), diaphragm 70 pushes spring 68, pulls shuttle valve 76, and closes the valve so that air does not flow from fan inlet 80 into tank 12. The spring 68 is selected such that the spring force corresponds to a desired threshold difference between the static pressure PS1 in the tank 12 or PS4 (e.g., the pressure in the secondary line 52). And static pressure PS2 in main line 22 or static pressure PS3 in meter housing 27. The pressure in the storage tank PS1 is released by air flowing from the tank outlet 36 and the seeds 26.

To illustrate these components more clearly, fig. 4 shows an exploded view of the valve 61. It should be understood that the shuttle valve 61 shown in fig. 3 and 4 is but one of many possible embodiments of a valve. In other words, one of ordinary skill in the art can implement the systems and methods described herein using any number of valve types.

As described above, controller 56 may control the operation of the valves to control static pressures PS1, PS2, PS3, and PS 4. One embodiment of a process 82 for controlling static pressure in a pneumatic dispensing system is shown in FIG. 5. Generally, the process 82 includes monitoring a static pressure in the storage tank (process block 84), the venturi section, or the meter housing 27 (process block 86). It is determined whether the static pressure in the tank is at a desired pressure above the static pressure in the venturi section or meter housing 27 (decision block 88) and a valve is opened to pressurize the tank when the static pressure in the tank is not above the static pressure in the capital-risk section or meter housing 27 (process block 90). In some embodiments, one or more steps of process 82 may be implemented by instructions stored on a tangible, non-transitory, computer-readable medium (e.g., memory 58) and executable by processing circuitry (e.g., processor 60).

In some embodiments, the controller 56 may monitor the static pressure SP1 in the storage tank 12 using the first pressure sensor 48 (block 84). More specifically, first pressure sensor 48 may output a signal to controller 56 indicative of static pressure PS1 in reservoir 12. The controller 56 may also monitor the static pressure SP4 in the auxiliary line 52 using the fourth pressure sensor 51 (block 84). First pressure sensor 51 may output a signal indicative of static pressure PS4 in auxiliary line 52 to controller 56. Likewise, the controller 56 may monitor the static pressure PS2 in the venturi section 44 using the second pressure sensor 49 (process block 86). More specifically, the second pressure sensor 49 may output a signal indicative of the static pressure ps2 in the venturi section 44 to the controller 56. The controller 56 may monitor the static pressure PS3 in the meter housing 27 using the third pressure sensor 50 (process block 86). More specifically, the third pressure sensor 50 may output a signal indicative of the static pressure PS3 in the meter housing 27 to the controller 56. Likewise, the controller 56 may monitor the static pressure PS4 in the auxiliary line 52 using the fourth pressure sensor 51 (process block 86). More specifically, the third pressure sensor 50 may output a signal indicative of the static pressure PS3 in the meter housing 27 to the controller 56.

The controller 56 may then compare the static pressure PS1 in the storage tank 12 or the static pressure PS4 in the secondary line 52 to the static pressure PS2 in the venturi 44 section or the static pressure PS3 in the meter housing 27 (decision block 88). When controller 56 determines that static pressure PS1 in storage tank 12 or static pressure PS4 in secondary line 52 is at least higher than static pressure PS2 in venturi 44 portion or static pressure PS3 in meter housing 27 (e.g., the difference between PS1 or PS4 and PS2 or PS3 is within a desired range), controller 56 may close valve or hold valve 54 closed and return to monitoring static pressure PS 8925 in storage tank 12 or static pressure PS4 in secondary line 52 (arrow 92).

On the other hand, when the controller 56 determines that the static pressure ps1 in the tank or the static pressure ps4 in the secondary line is not higher than the static pressure ps2 in the venturi 44 portion, the static pressure ps3 in the meter housing 27 reaches a desired threshold (e.g., the difference between ps1 or ps4 and ps2 or ps3 is not within a desired range), the controller 56 may instruct the valve 54 to open. Thus, the airflow 24 may flow into the tank 12 through the secondary line 52, thereby increasing the static pressure PS1 in the storage tank 12 or the static pressure PS4 in the secondary line 52. The controller 56 may then return to monitoring the static pressure in the storage tank 12 or the static pressure PS4 in the secondary line 52 (arrow 92).

It should be understood that the desired threshold or range of differences may be adjusted as desired. For example, the desired range of difference between static pressure PS1 in the tank 12 or PS4 in the secondary line 52 may be between 0.125 kpa and 1.246 kpa or between 0.125 kpa and 0.249 kpa for static pressure PS2 in the venturi 44 section or static pressure PS3 in the meter housing 27.

As previously mentioned, other embodiments may be based on various pressure sensor locations. For example, similar techniques may be used to monitor and control the difference between PS1 and PS2, PS4 and PS2, PS1 and PS3, PS4 and PS3, or PS3 and PS2, to maintain a threshold or acceptable difference between the measured pressure upstream of the meter housing 27 and the measured pressure downstream of the meter housing.

Accordingly, embodiments described herein may provide technical benefits of improving the consistency of seed dispensing in a produce dispensing system. More specifically, a valve may be used to adjust the static pressure in the tank based on the static pressure in the main conduit to reduce the possibility of an unexpected pressure change causing an interruption in seed flow. In some embodiments, the valve may be opened to supply air from the main line to the reservoir, thereby increasing the static pressure of the reservoir. In this way, the difference between the static pressure in the primary line and the static pressure in the tank can be kept within a desired range.

Claims (1)

1. A pneumatic dispensing system configured to dispense a granular product to an agricultural implement, wherein the pneumatic dispensing system comprises:

pneumatically conveying the particulate product to a main conduit of an agricultural implement by directing an air flow from a first portion of the main conduit having a larger cross-sectional area to a second portion of the main conduit having a smaller cross-sectional area; an air source fluidly coupled to a first portion of a main conduit, wherein the air source is configured to output an air flow; a secondary conduit fluidly coupled between the first portion of the primary conduit and a reservoir configured to store the particulate product; a valve assembly disposed along the secondary conduit fluidly coupled between the reservoir and the primary conduit, wherein the valve assembly comprises: a fan inlet fluidly coupled with the air source; a reservoir outlet fluidly coupled to the reservoir; a shuttle valve including a shuttle shaped aperture; a control pressure inlet fluidly coupled to the meter housing; and a diaphragm having a first side and a second side, the diaphragm coupled to the first side of the shuttle; wherein a first side of the diaphragm is exposed to a first static pressure in the reservoir through the reservoir outlet and a second side of the diaphragm is exposed to a second static pressure in the meter housing through the control pressure inlet, wherein the diaphragm is configured to move toward the tank outlet such that the shuttle aperture is aligned with the fan inlet when a first static pressure in the tank is not greater than a threshold amount of a second static pressure in the meter housing.

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